As the technology develops, an era of rapid development for electronic products comes, and various new electronic products, such as smart phones, tablet computers, notebook computers, smart TVs, etc., emerge in the market. These electronic devices cause great conveniences to our daily life.
The electronic devices should be charged frequently for continuous usage. Recently, it is a main trend to charge the electronic devices in a wireless manner. Existing wireless charging technologies are based on the Maxwell theories.
For a tablet electronic product, for example, an existing wireless charging technique is to charge the tablet electronic product by a charging pad.
Specifically, a flat coil for electromagnetic induction is provided inside the tablet electronic device, with an axis perpendicular to a front surface of the tablet electronic device on which a display panel is disposed. The flat coil for electromagnetic induction is in tight contact with the front surface or a back surface opposite to the front surface.
Also, a flat coil for electromagnetic induction is provided inside the charging pad, with an axis perpendicular to a charging surface of the charging pad. The flat coil for electromagnetic induction is in tight contact with the charging surface.
If the tablet electronic device needs to be charged, we can put it onto the charging pad, with its front or back surface against the charging surface of the charging pad. Then, the tablet electronic device can be charged.
However, the inventors found that there are some disadvantages in the wireless charging technologies.
For example, in a case where the tablet electronic device is to be charged by the flat coil for electromagnetic induction in tight contact with the front or back surface thereof, it is necessary to lay the front or back surface of the tablet electronic device against the charging pad to achieve wireless charging.
In other words, the tablet electronic device can be charged in a wireless manner only if its front or back surface is lying against the charging pad.